crista galli
Reading File
Searching the Web
crista galli anatomy ethmoid bone function
Finding Sources
Reading File
Finding Sources
Reading File
Reading File
Loading Image
Finding Sources
Reading File
Here is a detailed overview of the crista galli based on authoritative anatomy textbooks:
Crista Galli
What It Is
The crista galli (Latin: "cock's comb") is a large, triangular process of bone that projects superiorly from the midline of the superior surface of the cribriform plate of the ethmoid bone. It sits in the anterior cranial fossa, pointing upward into the cranial cavity.
- Gray's Anatomy for Students: "A large triangular process (the crista galli) at the midline on the superior surface of the cribriform plate anchors a fold (falx cerebri) of dura mater in the cranial cavity."
Location and Bony Relationships
The crista galli sits in the context of the ethmoid bone, which is one of the most complex bones of the skull. Key positional relationships:
- Inferiorly - the cribriform plate, which is perforated by 15-20 small foramina through which the olfactory nerve (CN I) fibers pass from nasal mucosa to the olfactory bulb
- Anteriorly - the foramen cecum, a small opening between the ethmoid and frontal bones that may transmit emissary veins connecting the nasal cavity to the superior sagittal sinus
- Further anteriorly - the frontal crest of the frontal bone (another falx attachment point)
- Laterally - the cribriform plate flanks the crista galli on both sides
- Posteriorly - the planum sphenoidale and sphenoid body
The crista galli defines the midline of the anterior skull base (KJ Lee's Essential Otolaryngology).
Primary Function
Its single most important role is as the anterior attachment point for the falx cerebri - the crescent-shaped dural partition that descends between the two cerebral hemispheres.
From Gray's Anatomy for Students: "The falx cerebri is a crescent-shaped downward projection of meningeal dura mater... It is attached anteriorly to the crista galli of the ethmoid bone and frontal crest of the frontal bone."
Surgical Significance
The crista galli is a key anatomical landmark in anterior skull base surgery:
- Transcribriform approach - surgeons must detach the dura and remove the base of the crista galli with a drill before dural opening, so that the falx attachment can be cauterized and divided
- Transfrontal approach - the crista galli is a key listed landmark for orienting the surgeon at the anterior skull base
- CT imaging - a widened foramen cecum and bifid crista galli on CT do not necessarily indicate intracranial extension of disease, but a normal crista galli and foramen cecum effectively rule out intracranial extension (Scott-Brown's Otorhinolaryngology)
- Midline anchor - because the falx cerebri attaches here, division or disruption of the crista galli region during surgery requires cauterization of the falx to prevent CSF or vascular complications
Ethmoid Bone in Brief
The crista galli is part of the ethmoid bone, which also consists of:
| Part | Location / Role |
|---|---|
| Cribriform plate | Roof of nasal cavity; perforated for CN I fibers |
| Crista galli | Midline superior projection; falx cerebri anchor |
| Perpendicular plate | Descends into nasal septum (upper part) |
| Ethmoidal labyrinths (x2) | Lateral boxes containing ethmoidal air cells |
| Orbital plate (lamina papyracea) | Forms medial orbital wall |
| Superior and middle conchae | Project into nasal cavity; increase surface area |
Dural Partition Context
The four dural partitions and their bony anchors:
- Falx cerebri - attaches to crista galli (anteriorly) and tentorium cerebelli (posteriorly)
- Tentorium cerebelli - attaches to occipital bone and petrous temporal bone
- Falx cerebelli - attaches to internal occipital crest
- Diaphragma sellae - covers the hypophyseal fossa in the sella turcica
Sources: Gray's Anatomy for Students, p. 1002 & 1212; Cummings Otolaryngology Head and Neck Surgery, p. 3384; KJ Lee's Essential Otolaryngology; Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 1
This is a shared conversation. Sign in to Orris to start your own chat.